OCI 7 Datasource exclude option

Have some HDS arrays attached to a HDvM instance which are waiting for decommissioning and we no longer need to monitor but I've tried placing excludes in the Datasource config both on Array name and IP address(es) but nothing appears to have changed. Not sure if I'm then meant to delete the arrays from OCI console or they are meant to show as offline so I can then delete... they still appear in the Web console under the datasource after the excludes are in place so I'm assuming it's not working so well ... ??